#!/bin/bash
#
# Copyright 2015 Hewlett-Packard Development Company, L.P.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#

# dib-lint: disable=safe_sudo

if [ "${DIB_DEBUG_TRACE:-0}" -gt 0 ]; then
    set -x
fi
set -eu
set -o pipefail

source $_LIB/common-functions

if [ -f ${TARGET_ROOT}/.extra_settings ] ; then
    . ${TARGET_ROOT}/.extra_settings
fi
ARCH=${ARCH:-x86_64}
if [ $ARCH = amd64 ]; then
    ARCH=x86_64
fi
# Calling elements will need to set DISTRO_NAME and DIB_RELEASE
# TODO Maybe deal with DIB_DISTRIBUTION_MIRROR
http_proxy=${http_proxy:-}
YUM=${YUM:-yum}

WORKING=$(mktemp --tmpdir=${TMP_DIR:-/tmp} -d)
EACTION="rm -r $WORKING"
trap "$EACTION" EXIT

YUM_CACHE=$DIB_IMAGE_CACHE/yum
mkdir -p $YUM_CACHE

# Note, on Debian/Ubuntu, %_dbpath is set in the RPM macros as
# ${HOME}/.rpmdb/ -- this makes sense as RPM isn't the system
# packager.  This path is relative to the "--root" argument
_RPM="rpm --dbpath=/var/lib/rpm"

# install the [fedora|centos]-[release|repo] packages inside the
# chroot, which are needed to bootstrap yum/dnf
#
# note this runs outside the chroot, where we're assuming the platform
# has yum/yumdownloader
function _install_repos {
    local packages
    local rc

    # pre-install the base system packages via rpm.  We previously
    # just left it up to yum to drag these in when we "yum install
    # yum" in the chroot in _install_pkg_manager.  This raised a small
    # problem that inside the empty chroot yum went ahead and did a
    # mkdir for /var/run to put some pid file in, which then messed up
    # the "filesystem" package making /var/run a symlink to /run
    # ... which leads to odd issues with a running system.
    #
    # TODO: these packages still have some small %posttrans stuff that
    # depends on other packages (see rhbz#1306489) ... maybe the idea
    # is that they are only installed in one big transaction with the
    # rest of the system?  but we don't want to use yum to do this
    # (see above) so ...
    packages="basesystem filesystem setup "

    if [[ ${DISTRO_NAME} = fedora && ${DIB_RELEASE} -gt 29 ]]; then
        packages+="fedora-release-cloud fedora-release-common "
    else
        packages+="${DISTRO_NAME}-release "
    fi

    # Starting in F21 this was split into a separate package
    if [[ ${DISTRO_NAME} == 'fedora' ]]; then
        packages+="fedora-repos "
    fi

    # F27 started putting gpg keys into this separate package
    if [[ ${DISTRO_NAME} = fedora && ${DIB_RELEASE} -gt 26 ]]; then
        packages+="fedora-gpg-keys "
    fi

    # CentOS 8.1 split repositories and GPG keys out into subpackages
    if [[ ${DISTRO_NAME} = centos && ${DIB_RELEASE} -ge 8 ]]; then
        packages+="centos-repos centos-gpg-keys "
    fi

    # By default, parent elements (fedora-minimal, centos-minimal)
    # have a yum.repos.d directory in the element with a default repo;
    # this is copied to TMP_HOOK_PATH by the usual hook-copying
    # routines.  In the gate, environment.d files for the funtional
    # tests will set DIB_YUM_MINIMAL_BOOTSTRAP_REPOS -- this contains
    # mirrors correct for the region setup by contrib/setup-gate-mirrors.sh
    local repo=${DIB_YUM_MINIMAL_BOOTSTRAP_REPOS:-}
    if [[ -z ${repo} ]]; then
        # take in preference more specific subdirs
        if [[ -d ${TMP_HOOKS_PATH}/yum.repos.d/${DIB_RELEASE} ]]; then
            repo=${TMP_HOOKS_PATH}/yum.repos.d/${DIB_RELEASE}
        else
            repo=${TMP_HOOKS_PATH}/yum.repos.d
        fi
    fi

    # yumdownloader puts repo xml files and such into a directory
    # ${TMPDIR}/yum-$USER-random.  Since we don't need this once the
    # initial download happens, redirect TMPDIR for this call so we
    # can clean it up nicely
    local temp_tmp
    temp_tmp=$(mktemp -d)
    TMPDIR=${temp_tmp} yumdownloader --verbose \
        --releasever=$DIB_RELEASE \
        --setopt=reposdir=$repo \
        --destdir=$WORKING \
        ${packages} && rc=$? || rc=$?
    rm -rf ${temp_tmp}
    if [[ ${rc} != 0 ]]; then
        die "Failed to download initial packages: ${packages}"
    fi

    # --nodeps works around these wanting /bin/sh in some fedora
    # releases, see rhbz#1265873
    sudo $_RPM --root $TARGET_ROOT --nodeps -ivh $WORKING/*rpm

    # install the bootstrap mirror repos over the default ones, if
    # set.  we will remove this at the end so the final image has
    # regular mirrors
    if [[ -n ${DIB_YUM_MINIMAL_BOOTSTRAP_REPOS:-} ]]; then
        for repo in $TARGET_ROOT/etc/yum.repos.d/*.repo; do
            sudo mv $repo $repo.USING_MIRROR
        done
        sudo cp ${DIB_YUM_MINIMAL_BOOTSTRAP_REPOS}/* \
            $TARGET_ROOT/etc/yum.repos.d/
    fi

    if [[ -n ${DIB_YUM_MINIMAL_EXTRA_REPOS:-} ]]; then
        sudo cp ${DIB_YUM_MINIMAL_EXTRA_REPOS}/* \
            $TARGET_ROOT/etc/yum.repos.d/
    fi
}

# _install_pkg_manager packages...
#
# install the package manager packages.  This is done outside the chroot
# and with yum from the build system.
# TODO: one day build systems will be dnf only, but we don't handle
# that right now
function _install_pkg_manager {
    # Install into the chroot, using the gpg keys from the release
    # rpm's installed in the chroot
    sudo sed -i "s,/etc/pki/rpm-gpg,$TARGET_ROOT/etc/pki/rpm-gpg,g" \
        $TARGET_ROOT/etc/yum.repos.d/*repo

    # See notes on $_RPM variable -- we need to override the
    # $HOME-based dbpath set on debian/ubuntu here.  Unfortunately,
    # yum does not have a way to override rpm macros from the command
    # line.  So we modify the user's ~/.rpmmacros to set %_dbpath back
    # to "/var/lib/rpm" (note, this is taken relative to the
    # --installroot).
    #
    # Also note, we only want this done around this call -- this is
    # the only place we are using yum outside the chroot, and hence
    # picking up the base-system's default rpm macros.  For example,
    # the yumdownloader calls above in _install_repos want to use
    # ~/.rpmdb/ ... there is nothing in the build-system /var/lib/rpm!
    #
    # Another issue we hit is having to set --releasedir here.  yum
    # determines $releasevar based on (more or less) "rpm -q
    # --whatprovides $distroverpkg".  By default, this is
    # "redhat-release" (fedora-release provides redhat-release) but
    # some platforms like CentOS override it in /etc/yum.conf (to
    # centos-release in their case).  You can't override this (see
    # [1]), but setting --releasever works around this.
    #
    # [1] https://bugzilla.redhat.com/show_bug.cgi?id=1287333
    (
        flock -w 1200 9 || die "Can not lock .rpmmacros"
        echo "%_dbpath /var/lib/rpm" >> $HOME/.rpmmacros

        local _lang_pack=""
        local _extra_pkgs=""

        if [[ $DISTRO_NAME == "fedora" ]] || \
            [[ $DISTRO_NAME == "centos" && $DIB_RELEASE -ge 8 ]]; then
            # glibc from F24 onwards has split locales into "langpack"
            # packages.  Host yum doesn't understand the
            # weak-dependencies glibc now uses to get the
            # minimal-langpack and chooses a random(ish) one that
            # satisfies the locale dependency (rhbz#1349258).
            # Work-around this by explicitly requring the minimal and
            # english (for en_US.UTF-8) pack.
            _lang_pack="glibc-minimal-langpack glibc-langpack-en"
        fi

        # Yum has some issues choosing weak dependencies.  It can end
        # up choosing "coreutils-single" instead of "coreutils" which
        # causes problems later when a package actually requires
        # coreutils.  For more info see
        #  https://bugzilla.redhat.com/show_bug.cgi?id=1286445
        # Really all we can do is pre-install the right thing
        _extra_pkgs+="coreutils "

        sudo -E yum -y \
            --disableexcludes=all \
            --setopt=cachedir=$YUM_CACHE/$ARCH/$DIB_RELEASE \
            --setopt=reposdir=$TARGET_ROOT/etc/yum.repos.d \
            --releasever=$DIB_RELEASE \
            --installroot $TARGET_ROOT \
            install $@ ${_lang_pack} ${_extra_pkgs} && rc=$? || rc=$?

        # Note we've modified the base system's .rpmmacros.  Ensure we
        # clean it up *always*
        # sed makes it easy to remove last line, but not last n lines...
        sed -i '$ d' $HOME/.rpmmacros; sed -i '$ d' $HOME/.rpmmacros;
        if [ $rc != 0 ]; then
            die "Initial yum install to chroot failed!  Can not continue."
        fi
    ) 9>$DIB_LOCKFILES/.rpmmacros.dib.lock

    # Set gpg path back because subsequent actions will take place in
    # the chroot
    sudo sed -i "s,$TARGET_ROOT/etc/pki/rpm-gpg,/etc/pki/rpm-gpg,g" \
        $TARGET_ROOT/etc/yum.repos.d/*repo
}

# Note this is not usually done for root.d elements (see
# lib/common-functions:mount_proc_dev_sys) but it's important that
# we have things like /dev/urandom around inside the chroot for
# the rpm [pre|post]inst scripts within the packages.
sudo mkdir -p $TARGET_ROOT/proc $TARGET_ROOT/dev $TARGET_ROOT/sys
sudo mount -t proc none $TARGET_ROOT/proc
sudo mount --bind /dev $TARGET_ROOT/dev
sudo mount -t devpts $(mount_dev_pts_options) devpts $TARGET_ROOT/dev/pts
sudo mount -t sysfs none $TARGET_ROOT/sys

# initalize rpmdb
sudo mkdir -p $TARGET_ROOT/var/lib/rpm
sudo $_RPM --root $TARGET_ROOT --initdb

# this makes sure that running yum/dnf in the chroot it can get
# out to download stuff
sudo mkdir $TARGET_ROOT/etc
sudo cp /etc/resolv.conf $TARGET_ROOT/etc/resolv.conf

# Bind mount the external yum cache inside the chroot.  Same logic
# as in the yum element to provide for yum caching copied here
# because the sequencing is wrong otherwise
sudo mkdir -p $TMP_MOUNT_PATH/tmp/yum
sudo mount --bind $YUM_CACHE $TMP_MOUNT_PATH/tmp/yum

_install_repos

# Install package manager

# We are somewhat fighting against the "yum" version on the host to
# get things installed correctly.  Fedora 27 onwards has a
# "curl-minimal" package that will get pulled in by default for the
# initial install (ianw: I think because the yum doesn't understand
# weak dependencies correctly).  This causes problems later if/when
# "curl" gets installed (you need to add --allowerasing to let dnf get
# rid of the old package).  To avoid this, just install the full curl
# and first up.  On Centos, it's different again and we need to
# specify libcurl as well, or the minimal libcurl packages come in
# causing similar problems.  *But* -- we can't also do that on Fedora
# it seems, as it seems like as part of the Fedora modular updates
# (https://docs.fedoraproject.org/en-US/modularity/) we can pick up
# seemingly mismatched libraries.
if [[ ${DISTRO_NAME} == 'fedora' ]]; then
    _install_pkg_manager dnf dnf-plugins-core curl
elif [[ ${DISTRO_NAME} == centos && $DIB_RELEASE -ge 8 ]]; then
    _install_pkg_manager dnf dnf-plugins-core curl libcurl
else
    _install_pkg_manager yum
fi

# we just installed yum/dnf with "outside" tools (yum/rpm) which
# might have created /var/lib/[yum|rpm] (etc) that are slighlty
# incompatible.  Refresh everything with the in-chroot tools
sudo -E chroot $TARGET_ROOT rpm --rebuilddb
sudo -E chroot $TARGET_ROOT ${YUM} clean all

# populate the lang reduction macro in the chroot
echo "%_install_langs C:en_US:en_US.UTF-8" | \
    sudo tee -a $TARGET_ROOT/etc/rpm/macros.langs > /dev/null

_base_packages="systemd passwd findutils sudo util-linux-ng "

# This package is split out from systemd on >F24, dracut is
# missing the dependency and will fail to make an initrd without
# it; see
#  https://bugzilla.redhat.com/show_bug.cgi?id=1398505
_base_packages+="systemd-udev "

# bootstrap the environment within the chroot; bring in new
# metadata with an update and install some base packages we need.
sudo -E chroot $TARGET_ROOT ${YUM} -y update
sudo -E chroot $TARGET_ROOT ${YUM} -y \
    --setopt=cachedir=/tmp/yum/$ARCH/$DIB_RELEASE \
    install ${_base_packages}

# Put in a dummy /etc/resolv.conf over the temporary one we used
# to bootstrap.  systemd has a bug/feature [1] that it will assume
# you want systemd-networkd as the network manager and create a
# broken symlink to /run/... if the base image doesn't have one.
# This broken link confuses things like dhclient.
# [1] https://bugzilla.redhat.com/show_bug.cgi?id=1197204
echo -e "# This file intentionally left blank\n" | \
    sudo tee $TARGET_ROOT/etc/resolv.conf

# set the most reliable UTF-8 locale
echo -e 'LANG="en_US.UTF-8"' | \
    sudo tee $TARGET_ROOT/etc/locale.conf
    # default to UTC
sudo -E chroot $TARGET_ROOT ln -sf /usr/share/zoneinfo/UTC \
    /etc/localtime

# cleanup
# TODO : move this into a exit trap; and reconsider how
# this integrates with the global exit cleanup path.
sudo umount $TMP_MOUNT_PATH/tmp/yum
sudo umount $TARGET_ROOT/proc
sudo umount $TARGET_ROOT/dev/pts
sudo umount $TARGET_ROOT/dev
sudo umount $TARGET_ROOT/sys

# RPM doesn't know whether files have been changed since install
# At this point though, we know for certain that we have changed no
# config files, so anything marked .rpmnew is just a bug.
for newfile in $(sudo find $TARGET_ROOT -type f -name '*rpmnew') ; do
    sudo mv $newfile $(echo $newfile | sed 's/.rpmnew$//')
done

sudo rm -f ${TARGET_ROOT}/.extra_settings
